This study investigates the effect of problem‐solving training on the interpersonal problem‐solving skills of mothers of children with special needs. The parallel randomised controlled trial was conducted between August 2021 and March 2022. A priori power analysis was conducted, and 98 mothers who met the inclusion criteria were included in the study. The analysis indicated that a sample size of 39 participants per group was required. Data were collected using a personal information form and the Interpersonal Problem Solving Inventory. The mothers were divided into control and experimental groups. The participants in the experimental group were given a problem‐solving training program, while the control group was not exposed to any intervention. There was no significant difference in the pre‐training test scores for any of the dimensions (p > 0.05). However, the post‐training test scores in the experimental group were significantly higher than post‐training test scores in the control group (p < 0.05). There were significant differences between the pre‐training and post‐training test scores in the experimental group (p < 0.05). Interpersonal problem‐solving skills can be improved by providing problem‐solving training to the mothers of children with special needs. Based on the findings of this study, it is recommended that psychiatric nurses provide training to protect and improve the wellbeing of children with special needs and their families.